Life-cycle welfare losses from rules-of-thumb asset allocation

How should workers invest over the life-cycle? Should they follow some typical prescriptions (“rules of thumb”) in personal finance implying higher equity investments when young? We show that the answer hinges on the risk of long-term unemployment spells, entailing permanent declines in workers’ future earnings prospects. Absent unemployment risk, extant prescriptions deliver portfolios that are close to optimal, implying negligible welfare losses. They instead lead to sizeable welfare losses (3%–9% of annual consumption) when the risk of human capital depreciation following long-term unemployment is considered and realistically calibrated to the U.S. labor market. These losses stem from excess risk taking when young investors face uncertainty about future labor and pension incomes. This result points to a new design for pension plans offered by long-term institutional investors.